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Presentation of African American pageants for children was an important aspect of the Harlem Renaissance in the early 20th century. The dramas emphasized the accomplishments and dignity of African Americans, and aimed to infuse children with the spirit to triumph in a racist society. They abided by sophisticated artistic rules and fulfilled the political imperative that the future of African Americans began with child development.

A high accuracy online flow rate measurement system has been used to determine the current flow rate scaling relationships for solutions of organic solvents doped with sodium iodide and for the ionic liquid 1-ethyl-3-methyl imidazolium tetrafluoroborate over a range of conductivities from 0.0025-1.3 S/m. The current flow rate trends for these solutions were found to exhibit a power law relationship similar to that described by previous researchers, where I (the electrospray current) is proportional to Q (the volumetric flow rate) to some power n. However, the exponent n of the current flow rate trends was found to differ from the theoretical predictions reported in the literature. A study including data from literature revealed the exponent of the current flow rate trends to be sensitive to the molar conductivity of the sprayed solution. [ABSTRACT FROM AUTHOR]

Life for many of the world's marine fish begins at the ocean surface. Ocean conditions dictate food availability and govern survivorship, yet little is known about the habitat preferences of larval fish during this highly vulnerable life-history stage. Here we show that surface slicks, a ubiquitous coastal ocean convergence feature, are important nurseries for larval fish from many ocean habitats at ecosystem scales. Slicks had higher densities of marine phytoplankton (1.7-fold), zooplankton (larval fish prey; 3.7-fold), and larval fish (8.1-fold) than nearby ambient waters across our study region in Hawai'i. Slicks contained larger, more welldeveloped individualswith competent swimming abilities compared to ambient waters, suggesting a physiological benefit to increased prey resources. Slicks also disproportionately accumulated prey-size plastics, resulting in a 60-fold higher ratio of plastics to larval fish prey than nearby waters. Dissections of hundreds of larval fish found that 8.6% of individuals in slicks had ingested plastics, a 2.3-fold higher occurrence than larval fish from ambient waters. Plastics were found in 7 of 8 families dissected, including swordfish (Xiphiidae), a commercially targeted species, and flying fish (Exocoetidae), a principal prey item for tuna and seabirds. Scaling up across an ~1,000 km2 coastal ecosystem in Hawai'i revealed slicks occupied only 8.3% of ocean surface habitat but contained 42.3% of all neustonic larval fish and 91.8% of all floating plastics. The ingestion of plastics by larval fish could reduce survivorship, compounding threats to fisheries productivity posed by overfishing, climate change, and habitat loss. [ABSTRACT FROM AUTHOR]

The rapid developments in micro-technologies and the introduction of modularity and standardization into system designs, present significant opportunities for cost reduction in the design and development of satellite systems. However, the high cost of space launch has become a major hindrance to capitalizing on these opportunities. Therefore, seeking appropriate launch opportunities and reducing launch costs might contribute to further growth of the space market. This paper focuses on the analysis of dedicated launch costs factoring in the effect of launch reliability, which in return, can enable the optimization of system designs. Applying a value-centric architecture, system characteristic space is introduced as the design space to define the characteristics of different systems. Based on our launch vehicle database, the launch cost and reliability of different families of launch vehicles are investigated, where the reliability is calculated using a modified two-level Bayesian analysis. The factors of launch cost and reliability are subsequently integrated into the expected launch cost, acting as the objective function for the analysis and optimization process associated with the manufacturing cost of satellites. Through reviewing and redesigning a few classical launch cases, the effectiveness and applicability of the design architecture proposed are validated. [ABSTRACT FROM AUTHOR]

The rapid development of emerging concepts and technologies, e.g., modularity, standardization, and fractionation, has resulted in the miniaturization of satellites and simplification of mission design, as well as a move towards more responsive and economical systems. However, the current customized and labor-intensive design philosophy is not naturally appropriate for enabling the application of these concepts and technologies. Therefore, a value-centric architecture for spacecraft design and certification is proposed in this paper to address this need. Firstly, the characteristics of different types of spacecraft are compared and summarized. In parallel, a survey on the current design and certification frameworks of large and complex systems is carried out. Taking in the experience of the frameworks, a generic design and certification architecture is developed from a value-centric perspective. Apart from keeping the critical advantages from the traditional methodologies, the new approach is capable of solving the problems inherent themselves. The results of a preliminary case study clearly show that the approach proposed can effectively capture, analyze, and optimize the value of different system designs, appealing to the growth of the space market. [ABSTRACT FROM AUTHOR]

Neurotransmitter receptors partition into nanometer-scale subdomains within the postsynaptic membrane that are precisely aligned with presynaptic neurotransmitter release sites. While spatial coordination between pre- and postsynaptic elements is observed at both excitatory and inhibitory synapses, the functional significance of this molecular architecture has been challenging to evaluate experimentally. Here we utilized an optogenetic clustering approach to acutely alter the nanoscale organization of the postsynaptic inhibitory scaffold gephyrin while monitoring synaptic function. Gephyrin clustering rapidly enlarged postsynaptic area, laterally displacing GABA A receptors from their normally precise apposition with presynaptic active zones. Receptor displacement was accompanied by decreased synaptic GABA A receptor currents even though presynaptic release probability and the overall abundance and function of synaptic GABA A receptors remained unperturbed. Thus, acutely repositioning neurotransmitter receptors within the postsynaptic membrane profoundly influences synaptic efficacy, establishing the functional importance of precision pre-/postsynaptic molecular coordination at inhibitory synapses. [Display omitted] • GABA A Rs clusters are normally localized directly opposite GABA release sites • Acutely clustering gephyrin disperses GABA A Rs within the postsynaptic membrane • Gephyrin clustering impairs synaptic transmission but not GABA A R number/function • Precise GABA A R alignment with GABA release is required for optimal synapse function Olah et al. developed an optogenetic approach to acutely disrupt the nanoscale localization of postsynaptic neurotransmitter receptors relative to presynaptic neurotransmitter release sites. They use the approach to establish the functional importance of precision pre-/postsynaptic nano-alignment at GABAergic inhibitory synapses. [ABSTRACT FROM AUTHOR]